A hybrid vehicle, which refers to a motor vehicle equipped with an electric motor and an internal combustion engine in combination, is known to enjoy increased fuel economy and reduced upkeep costs and is an environmentally friendly vehicle that produces an extremely low level of exhaust emission, thus helping to reduce air pollution.
Such a hybrid vehicle includes a battery for supplying the electric motor with an electric power, a motor control unit for controlling the electric motor, a DC-DC converter for properly converting an electric voltage of the battery and a cooling system for cooling the battery. In particular, the cooling system is adapted to cool the battery that emits heat of a high temperature, thereby preventing any overheat of the battery and prolonging the life span thereof.
As one example of the cooling system, there is known an air-cooled cooling system that includes, as illustrated in FIG. 1, an intake duct 1 through which the air is drawn from a passenger compartment, an introduction duct 5 for leading the air thus drawn to a battery case 3 and an exhaust duct 7 through which the air in the battery case 3 is discharged to the outside.
The air-cooled cooling system is designed to draw the air from the passenger compartment and introduce the air thus drawn into the battery case 3. This enables the air introduced into the battery case 3 to cool the battery (not shown) situated within the battery case 3.
One drawback of such a conventional cooling system is that it is configured to cool nothing but the battery and has no ability to cool the motor control unit and the DC-DC converter. This poses a problem in that separate cooling devices need to be provided to cool the motor control unit and the DC-DC converter.
More importantly, the cooling devices for cooling the motor control unit and the DC-DC converter need to be installed independently of each other. This is problematic in that the number of components is increased as well and hence the cooling system becomes structurally complex with an attendant increase in production costs.